STV2247H(2009) View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
STV2247H Datasheet PDF : 86 Pages
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STV224X, STV228X, STV223X - FUNCTIONAL DESCRIPTION
green DC levels for black point adjustment takes The APR function can be enabled or disabled via
place via the bus.
the I²C bus.
3.4.9 Bus-controlled Contrast & Saturation
APR ON when register 10 hex d0 = 1 and register
The Contrast Control regulates internal RGB, ex- 07 hex d6 = 0.
ternal RGB and OSD RGB inputs. The maximum 3.4.16 RGB Peak Limitation
attenuation on internal and external RGB inputs is
-24 dB and is limited to -12 dB for OSD RGB in-
puts. The bus-controlled saturation range is 50 dB.
The APR function can be switched into an RGB
Peak Limitation function via the I²C bus: register
07 hex, data d6 = 1 and register 10 hex d0 = 1.
3.4.10 Bus-controlled Brightness & Sharpness For this purpose, the APR threshold, tracked with
The total brightness range is 60% of the black-to- the contrast for the APR function, is changed in a
white amplitude at maximum contrast. The bright- fixed threshold that is independent of the contrast.
ness control regulates all RGB sources (internal, In this case, the APR threshold I²C control should
external and OSD). Bus-controlled Sharpness be set to its maximum value.
(peaking) is provided in PAL/SECAM/NTSC
standards.
) 3.4.11 Bus-controlled Coring on Sharpness
t(s When the Coring-on-sharpness function is
switched ON, the peaking function is not active on
c low amplitude signals (below 10 IRE).
u 3.4.12 Black Stretch
d The Black Stretch circuit can be disabled via the
ro bus. Two modes are provided, one to be used
when the video signal is transmitted with a set-up
P (7.5IRE set-up in NTSC), the other to be used
te when the video signal is transmitted without a set-
up (PAL/SECAM).
le 3.4.13 Bus-controlled Blue Screen
o The bus-controlled Blue Screen feature is used to
s insert a blue background on the screen when no
b video is available. The RGB OSD can be dis-
played when the blue screen is active.
- O 3.4.14 White Insertion
) This function is used to force a full white screen at
t(s RGB output via the I²C bus or during Soft mode at
Powerdown.
c 3.4.15 Automatic RGB Peak Regulation (APR)
u The APR function is used to take advantage of the
d total RGB output range. APR circuits detect the
ro peak level of the RGB outputs (before OSD inser-
tion) and regulate the RGB gain (contrast) so that
P signals above the APR threshold are limited. For
example, at maximum drive and contrast levels
te with the APR function switched OFF, the 100 IRE
input signal gives 3 V(B/W) to the RGB outputs.
leWith APR ON and the APR threshold at 70 IRE,
othe 70 IRE input signal gives 3 V (B/W) at RGB
s outputs. For input signals above 70 IRE, the APR
b will decrease the RGB gain so that amplitude at
3.5 CHROMA CIRCUIT
3.5.1 PAL/SECAM/NTSC Decoders
SVHS Chroma input; bus-controlled SVHS mode.
– 30 dB Automatic Color Control (ACC) range.
The ACC function is an automatic gain control of
the color amplifier.
– Integrated chroma base band delay line and ON/
OFF bus control.
– Automatic standard identification, with possibility
of forcing the standard via the bus.
– 3-crystal application capability for the South
American market:
The first crystal on Pin XTAL1 (3.5X MHz only),
the second crystal on Pin XTAL2 (3.5X MHz on-
ly), and the third crystal on Pin XTAL3/BTUN
(3.5X MHz only, used for PAL/NTSC application
only).
3.5.2 PAL/NTSC Decoder
ACC carried out by peak detector on synchronous
demodulation of the burst.
Fully-integrated killer function.
VCO using two standard crystals: 4.43 MHz and
3.58 MHz. One crystal is internally selected de-
pending on the standard selection. A third crystal
can be used in PAL/NTSC applications only.
VCO reference signal is available on Pin X1.
– 4.433619 MHz Crystal specification.
Mode of operation: serial resonance (without
load capacity),
Motional capacitance: CM = 13fF ±3fF,
Shunt capacitance: CP < 7pF,
Serial resistance: RS < 70Ω.
the RGB output is always 3 V (B/W). The APR – 3.579545 MHz Crystal specification (NTSC M).
gain control voltage is memorized on an external
Mode of operation: serial resonance (without
capacitor where the gain decrease is very fast and
load capacity),
the gain increase is very slow (several frames).
Motional capacitance: CM = 11fF ±3fF,
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